Last month, Americans were unnerved by slumping stock markets and impeded from shopping by an unusually cold and snowy January that, because of high heating bills, could hurt retail sales into the spring, analysts said.

A group of nine retailers that report comparable monthly sales posted a 3.6 percent rise for January, below the 4.9 percent pace a year earlier, according to Thomson Reuters.

Some chains managed to register sales gains, but those came either at the expense of rivals or profit margins.

Costco Wholesale Corp (COST.O) said its same-store sales rose 5 percent in January, with fresh food a popular item for its bargain-seeking members. That contrasted with a quarterly decline at rival Sam’s Club, a unit of Wal-Mart Stores Inc (WMT.N). Costco’s shares rose 3.4 percent.

Victoria’s Secret parent L Brands Inc (LB.N) posted a much bigger-than-expected jump of 9 percent in comparable sales, sending its shares up more than 4 percent.

But L Brands also said its profit margin would be much lower after it stepped up discounts and extended sales events. The retailer expects only modest sales gains in February.

Gap Inc (GPS.N) reported a better than expected 1 percent increase, with its low-price Old Navy stores helping it overcome a 10 percent decline at its Banana Republic chains.

FOUL WEATHER, FOUL MOOD

The consumer mood soured last month. The Thomson Reuters/University of Michigan’s consumer sentiment index slipped to 81.2 in January from 82.5 in December. Confidence fell acutely among households with annual incomes below $75,000.

Kohl’s Corp (KSS.N), which is not in the Thomson Reuters tally, said sales in January were “significantly” lower than expected as shoppers stayed away, and the department store chain lowered its profit forecast.

It reported a 2 percent decline in quarterly comparable sales - those online and at stores open at least a year - despite a good start to the holiday season.

Still, Kohl’s shares rose 3.5 percent, in part because the sales shortfall came from having a low level of clearance inventory. Stifel Nicolaus analyst Richard Jaffe said in a note that this would help profit margin.

Other stores have also posted poor reports of late.

Baird analyst Mark Altschwager estimated that comparable sales at J.C. Penney Co Inc (JCP.N) fell 3 percent last month. And last week, Wal-Mart said its profit for the fourth quarter ended January 31 would come in at or slightly below its forecast.

Getting shoppers into stores was still a challenge. Walgreen Co WAG.N managed to report a jump in comparable sales, but the drugstore chain’s traffic fell 2.2 percent.

The weather was unforgiving, with record cold and heavy snow last month in the Midwest and Northeast.